Late Bharatiya Janata Party leader Pramod Mahajan's son Rahul Mahajan, under treatment at a private hospital in Delhi following suspected drug abuse, was on Saturday taken off ventilator support as he showed signs of improvement in his condition.

"The condition of Rahul Mahajan, who was admitted on Friday, has gradually improved over the last 12 hours. After due assessment of clinical status and investigation, our team of doctors found his vital parameters inproving," a medical bulletin released by the Apollo hospital said.

It said Mahajan has been weaned off the ventilator on Saturday morning and is under close observation and monitoring in the ICU.

Doctors said Rahul also regained consciousness for brief intervals overnight.

"He is in bouts of consciousness, but only at intervals. However, it cannot be called prolonged consciousness," Karan Thakur, a hospital spokesman, told reporters.

Thakur said Rahul was serious, but "out" of critical condition.

Doctors, the spokesman added, have conducted gastric and toxicology tests on the 31-year-old patient and are awaiting the reports.

Mahajan's mother Rekha Mahajan, sister Poonam and his uncle and former Maharashtra deputy chief minister Gopinath Munde were present at the hospital.